The absorption and luminescence spectia of Chl C in solusion have been analyzed.The energy levels of molecular orbital

charge density and heteroplar bond of π-electrons have been calculated quantitatively for Chl C by approximate method of Huckel molecular orbital(HMO).The sensitized fluorescence between Chl C and O

2

has been analyzed qualitatively.Since the absorption of biomolecules arises from electronic transition of co-jugated π-election

only π-electrons at the porphyrin frame are considered in the calculation of the energies of molecular orbits.